Telephone system



Mara 9, 1937. A, J, pAms -l 2,073,587

TELEPHONE SYSTEM Filed NOV. 27, 1955 //v1 /v TOR A NTHU ram/51 A A T TOR/V5 Y Patented Mar. 9, 1937 ITED STATES PATENT OFFICE 11 Claims.

My invention relates to the signaling or annunciator phase of communicating systems and particularly to a system wherein a visual or silent and/or an audible signal is emitted to attract attention at a subscriber's station in response to a flow of signaling current in the associated telephone circuit.

My invention more particularly relates to the association with a telephone circuit of an electric circuit having a separate source of energy and including a visual signaling device which, through the means associating the two circuits, is operated in a predetermined manner when a signaling current energizes the telephone circuit. In view of the fact that the visual signaling circuit is dependent upon a source of energy separate from that feeding the telephone circuit and in order to insure continuity ofservice, that is, the emission of a signal of one character or another when the telephone signaling circuit is energized, my invention has for a first object the provision of means for efiecting an operation of the annunciator in the telephone circuit in the event of a failure of the visual signal or the failure of power in its circuit.

Obviously, a visual signaling device is provided in order that a silent signal may be emitted at, for example, a subscribers station in a telephone system where quietness is desirable. In some instances, circumstances may require intermittent absences of a person from view of the visual signal. Hence, my invention has for another object, the provision of a manual control whereby both the visual and the audible signaling device may be connected to operate simultaneously.

A still further object resides in the provision of a device embodying the circuit of the above character which is simple in construction, has a comparatively low cost of manufacture and may be easily installed and adapted to existing telephone subscribers installations.

With these and other objects in view my invention includes the novel elements and the combinations and arrangements thereof described be- 5 low and illustrated in the accompanying drawing in which- Fig. l is a wiring diagram of my invention in its preferred form; and

Fig. 2 is a perspective view of a motor operated 5 switch representative of one of the elements incorporated in my device.

Referring to the drawing and particularly to Fig. 1, l indicates an incandescent lamp which is connected through legs 2 and 3 to the second- 55 ary 4 of a transformer 5, the motor 5 of a motoroperated switch, indicated generally at l and,

source of electrical energy, preferably the ordinary, commercial, 110 volt supply. The motor 6, which, it will be noted, is in series with the lamp 5, is designed to draw such a small wattage that the lamp remains normally unilluminated.

In order to produce an illumination of the lamp 5, the armature H of a relay 12 is connected through a conductor 93 to one side of motor 6 and a contact i l of relay l2, with which armature M is adapted to engage, is connected through conductor E5 to the other side of motor 6. When relay I2 is energized, armature l l thereof engages contact ill and, it is evident, shunts out motor 6 and effects an illumination of lamp l.

The circuit, above described, comprises those means which are subjected to a commercial lighting supply of electrical energy. It should be here noted that transformer 5 could be dispensed with but that due to the inadvisability of carrying comparatively high voltage, e. g., 110 volt, lines in telephone line conduits, I prefer to use a step-down transformer as indicated at 5 which supplies at its secondary approximately 24 volts.

The coil of relay l2 is connected in the telephone circuit with which the incandescent lamp circuit, above described, is associated. Conductors l6 and W represent the telephone trunk lines and are shown terminating at the terminals 98 and Hi, respectively, of the subscribers station. The receiving and transmitting sets are not shown and only that portion of the telephone circuit including the annunciator or bell is illustrated which is deemed necessary in order clearly to show the interconnection and arrangement of the circuits of my invention and the relative disposition of the electrical devices therein. The manner of connecting the receiver and transmitter to the terminals illustrated is well known in the art.

The telephone annunciator or bell 29 is connected between the terminals 2! and 22. Terminal it is connected through conductor 23, condenser 24 and conductor 25 to terminal 2| and terminal 22 is connected through conductor 26 to a movable contact arm2l of the motor-operated switch l. A fixed contact 2% of switch l with which arm 2? is adapted to engage, as hereinafter described, is connected through conductors 29 and 30 to terminal 59. In Fig. 1, the motor-operated switch is illustrated diagrammatically and a projection 33 is shown which is secured to the shaft of motor 6 and is adapted to urge the arm 21 out of engagement with contact 28. Switch 1, however, is illustrated in more detail in Fig. 2. When arm 21 lies in engagement with contact 26, the bell 26 is connected across the telephone trunk lines I6 and I1 and, assuming a signaling current flows in said trunk lines, an audible signal is emitted. Relay I2 is also connected across the telephone trunk lines It and I1. One end of the coil thereof is connected through conductor M to conductors 28 and 38 and the other end is connected through conductor 32 to terminal 2!. Hence, relay I2 is energized when signaling current flows in the trunk lines and the armature II thereof is-picked up and engages contact I i thereby shunting out the motor 6 and effecting an illumination of the incandescent lamp I.

Relay 32 comprises the means employed to as sociate the telephone circuit and the commercial lighting circuit whereby an energizaticn or flow of signaling current in the telephone circuit effects a predetermined operation of the lighting circuit. However, it is desirable that one form of signal or another be emitted at all times. In other words, in order to insure the emission of an audible signal, that is, an operation of bell 26, in the event of a failure of operation of the visual signal, that is, lamp I or its associated circuit, I have provided means comprising the motor-operated switch 1. It will be noted that motor 6 derives energy from the lighting service mains and in the normal, energized position, assuming motor 6 rotates in a clockwise direction, the projection 33 permits arm 21 to remain out of engagement with contact 28, thereby maintaining the circuit to bell 26 open. It is to be understood that the rotor of motor 6 is designed to return to a predetermined position when unenergized and in such position urges arm 21 in engagement with contact 28. Hence, motor 6,

being normally energized in the lamp signaling circuit, maintains the bell 2U disconnected from the telephone circuit so that, upon an energization of said circuit, no audible signal will be emitted but relay [2 will be energized to shunt motor 6 thereby effecting an illumination of lamp I.

My invention is primarily adapted for use with automatic telephone systems that is, systems wherein a ringing current supply is automatically connected in circuit with the subscribers station when the connection has been completed between the calling and the called parties. The ringing or signaling current is supplied from the central station, it being understood that a commutator is there provided and interposed between the source of supply and common, ringing current, -bus bars whereby an intermittent signaling current is transmitted over the telephone trunk lines. This current would, of course, if the bell 20 were not maintainedin open circuit by. the motor-operated switch 1, effect an intermittent ringing of the bell. On the other hand, it effects an intermittent energization of the relay I 2 whereby the motor 6 of switch 1 is intermittently shunted and lamp I is intermittently illuminated. Due to the design of the commutator at the central station, the signaling current is supplied for approximately two seconds and cut off for approximately four seconds. Relay I2, therefore, is energized for two seconds and deenergized for four seconds and the motor 6 is shunted during the two second period. It will be remembered that the rotor of motor 6 is designed to return to a predetermined position when unenergized and in such position urges arm 21 in contact with contact 28. Hence, when motor 6 is shunted, the rotor thereof starts its return movement. However, it is so designed that the period of time required by the rotor to return from its energized position and effect a closure of the switch 1 is greater than. two seconds or the period during which said motor is shunted.

A suitable design for the motor-operated switch 1 is illustrated in Fig. 2 wherein the projection 33 and arm 21 are shown as combined in the form of a contact arm 34 which is secured to and movable by the motor shaft 35. Ann 341 is shown in a position intermediate and spaced from the contact 28 and stop 36 for clearness of illustration. One end of a spiral springi-ll is also secured to shaft 35 and the other end thereof is secured at 38 to the base 39 upon which the elements of the switch are mounted. The motor is adapted to rotate upon energization in the'direction of the arrow A against the resistanceoifered by spring 31 and moves arm 3d until it engages the stop 36. When power is cut off to motor 6, spring 31 rotates shaft 35 in the opposite direction until arm a l engages contact 28. The arm 32, obviously, is insulated from shaft 35 because it controls a circuitwhich is con nected to the telephone lines whereas motor 60 is supplied from the electric service mains. Furthermore, spring 31 is designed slowly to return the arm 3 in the direction of contact 28 and the period of time required thereby to move arm 3Q from stop 36 to contact 28 is greater than two seconds. Hence, assuming that the energized motor 6 is shunted by an operation of relay I2, the relay will become deenergized before arm 36 engages contact 28 and the bell circuit will not be completed. It should also be noted that motor 6 is designed to produce only a relatively small torque and spring 31 is designed in accordance therewith so that the desired, timed operation of the switch arm E l is effected.

It is to be understood that equivalent mechanisms may be employed to perform the same function as motor-operated switch 1 such, for example, as a delayed relay or other suitable, electrical device and, therefore, I do not wish to limit this element of my invention to the exact means disclosed.

In order to permit the subscriber to connect the bell in circuit in the event he so desires, I have provided the switch dB, the contact M of which is connected through conductor I2 to conductor 3D and the arm 63 of which is connected through conductor M to conductor 26. It will be evident, by tracing the circuit, that switch 86 comprises a manual means for connecting the bell 20 across the mains I6 and I1 which, of course, may likewise be accomplished by a deenergization of motor 6 and a closure of switch 1. Switch 46 may be closed when, for example, the subscriber intends to go where the visual signal cannot be seen and when the switch is so closed, both a visual and an audible signal emission will be simultaneously effected.

The operation of my device is as follows. Assuming the electric service mains 9 and. III are energized, motor 6 is energized, maintaining switch 1 open and the incandescent lamp I is extinguished. Assuming also that switch t!) is open and a signaling current flows through the telephone trunk lines I6 and [1, the bell is in open circuit due to the fact switch 1 is open and no audible signal will, therefore, be given. The

relay 112, however, will be energized by the signaling current and armature l I thereof will be picked up and engage contact M thereby shunting motor 6 and effecting an illumination of lamp i. As hereinbefore indicated, the signaling current of automatic telephone systems is intermittent and relay i2 will, therefore, be periodically energized. Furthermore, the period of time required for motor 6 to close switch I is greater than that during which signaling current flows. The bell or audible signaling device, will not, therefore, be actuated and the lamp will flash or become periodically illuminated in response to the intermittent fiow of current in the telephone circuit. In the event of a power failure in the electric service mains or should the lamp 5 be removed or become burned out, no current, obviously, will fiow through the lamp circuit and motor 6 will become deenergized thereby closing the switch I and connecting bell 28 across the telephone trunk lines it and ill. Hence, if, for any reason, the visual signaling device is rendered inoperative, the audible signaling device will be operated and the emission of one character of signal or another is insured.

From the foregoing description of my invention in its preferred form, it is evident that a visual signal may be effected in response to an energization of. a telephone circuit, or, at the will of the subscriber, a simultaneous emission of both an audible and visual signal may be effected. As hereinbefore disclosed, the visual signal transpires when lamp i is intermittently illuminated. Furthermore, the visual signal is effected in response to the usual telephone'signaling current and, obviously, when the subscriber answers the signal or the calling party hangs up, the signaling operation of the lamp is automatically terminated in the same manner as the bell is silenced in the present automatic telephone systems. In addition, my invention, though employing a separate source of supply for the incandescent lamp from that supplying the telephone circuit, insures through the medium of the motor-operated switch ii, an operation of the bell in the event the lamp fails to function or its circuit is defective. This latter feature of my invention is very desirable inasmuch as the maintenance of a continuous and uninterrupted service is of prime importance where telephone circuits and apparatus is concerned.

It is to be understood that I am not limited to the various electrical means illustrated and described as incorporated in the circuits of my invention nor to the precise circuits disclosed in order to form an operative device of the character described, but equivalent means and circuits may be substituted for those illustrated with comparable results. While I have, therefore, described my invention in its preferred embodiment, it is to be understood that the specific means disclosed together with the arrangement of the circuits embodying the same are merely illustrative and that the words which I have used are descriptive rather than limitative.

Hence, changes within the purview of the appended claims may be made without departing from the true scope and spirit of my invention.

in its broader aspects.

What I claim is:

i. In a telephone system, a first electric circuit comprising telephone trunk lines and an audible signaling device connectible therewith, a

second electric circuit including a visual signaling device and means connected in series therewith for normally maintaining said audible signaling device in open circuit, and means connected in said first mentioned circuit and operable in response to an energization thereof for controlling an operation of said visual signaling device; said first mentioned means being operable upon a failure of current flow in said second mentioned circuit to connect said audible signaling device in said first mentioned circuit.

2. In a telephone system, a first electric circuit comprising telephone trunk lines and an audible signaling device connectible therewith, a second electric circuit including an incandescent lamp and means connected in series therewith for normally maintaining said audible signaling device in open circuit, and means connected in said first mentioned circuit and operable in response to an energization thereof for controlling an operation of said incandescent lamp; said first mentioned means being operable upon a failure of current flow in said second mentioned circuit to connect said audible signaling device in said first mentioned circuit.

3. In a telephone system, a first electric circuit comprising telephone trunk lines having a source of signaling current and an audible signaling device connectible therewith, a second electric circuit having a source of energy separate from that of said trunk lines and including a visual signaling device and means connected in series therewith for normally maintaining said audible device in open circuit but operable upon a failure of current flow therethrough to connect said audible signaling device in said first mentioned circuit, and means connected in said first mentioned circuit and operable in response to an energizaltion thereof for controlling an operation of said visual signaling device.

a. In a telephone system, a first electric circuit comprising telephone trunk lines having a source of signaling current and an audible signaling device connectible therewith, a second electric circuit having a source of energy separate from. that of said trunk lines and including an incandescent lamp and means connected in series therewith for normally maintaining said audible device in open circuit but operable upon a failure of current flow therethrough to. connect said audible signaling device in said first mentioned circuit, and means connected in said first mentioned circuit and operable in response to an energization thereof for efiecting an illumination of saidlamp.

5. In a telephone system, a first electric circuit comprising telephone trunk lines having a source of signaling current and an audible signaling device connectible therewith, a second electric circuit having a source of energy separate from that of said trunk lines and including a visual signaling device and means connected in series therewith for normally maintaining said audible device in open circuit but operable upon a failure of current fiow therethrough to connect said audible signaling device in said first mentioned circuit, and means connected in said first mentioned circuit and operable in response to an energization thereof for shunting said first mentioned means whereby an operation of said visual signaling device is effected.

6. In a telephone system, a first electric circuit comprising telephone trunk lines and an audible signaling device connectible therewith, a second electric circuit including a visual signaling device and means connected in a series circuit there= with adapted to draw current of a 'magnitude insumcient to efiect an operation of said visual signaling device, said device being operable to maintain said audible signaling device in open circuit but operable upon a failure of current flow in said second circuit to connect said audible signaling device in said first mentioned circuit, and means connected in said first mentioned circult and operable in response to a fiow of signaling current therein for efiecting an operation of said visual signaling device.

7. In a telephone system, a first electric circuit comprising telephone trunk lines and an audible signaling device connectible therewith, a second electric circuit including an incandescent lamp and means connected in circuit therewith adapted normally to render said lamp extinguished and maintain said audible signaling device in open circuit, and means connected in said first mentioned circuit and operable in response to a fiow of signaling current therein for effecting an illumination of said lamp; said first mentioned means being operable upon a failure of current flow in said second mentioned circuit to connect said audible signaling device in said first mentioned circuit.

8. In a telephone system, a first electric circuit comprising telephone trunk lines connected to a source of intermittent, signaling current and having an audible signaling device connectible therewith, a second electric circuit including a visual signaling device and means connected in circuit therewith adapted normally to maintain said audible signaling device in open circuit but operable upon a failure of current flow therethrough to connect said latter device in said first mentioned circuit, and means connected in said first mentioned circuit and operable in response to the flow of signaling current therein intermittently to shunt said first mentioned means whereby an intermittent operation of said visual signaling device is effected; the time required by said first mentioned means after deenergization with for normally maintaining said audible signaling device in open circuit but operable upon a failure of current flow therethrough to connect said audible signaling device in said first mentioned circuit, means connected in said first mentioned circuit and operable in response to an energizetion thereof for controlling an operation or" said visual signaling device and manually operable means for connecting said audible signaling means in said first mentioned circuit whereby a simultaneous audible and visual signal emission is effected in response to an energiaation of said first mentioned circuit.

10.. In a telephone system comprising a subscribersstation, the combination with an audible signaling device and a visual signaling device, said visual signaling device being operatively associated with the telephone circuit and adapted to emit a visual signal when signaling current flows in said telephone circuit, or" means connected in series with said visual device adapted operatively to associate said audible device with said circuit upon a failure or" operation of said visual device.

11. In a telephone system comprising a subscribers station, the combination with a bell and an incandescent lamp, said lamp being operatively associated withthe telephone circuit and adapted to emit a visual signal when signaling current fiows in said telephone circuit, of means connected in series with said lamp adapted operatively to associate said bell with said circuit upon a failure of illumination of said lamp when signaling current flows in said telephone circuit.

ANTHONY J. PARISSI. 

